Telegraph receiver utilizing electronic distributors



4, 1954 R. G. SCHULER 2677725 TELEGRAPH RECEIVER UTILIZNG ELECTRONIC DISTRIBUTRS ATTORNEY 4 1954 R. G. SCHULER 2677725 TELEGRPH RECEIVER UTILIZING ELECTRONIC DISTRIBUTORS Original F'iled Oct. 15, 1948 4 Sheets-Sheet 2 CHANNEL PHSE SQUARER FREOUENCY SHIFI'ING AND DIVIDER NE'IWORK MPI.IFIER INVENTOR 2 REGINALD G. SGHULER ATTORNEY May 4, 1954 SCHULER 2677,725

TELEGRPH RECEIVER UTILIZING ELECTRONIC DISTRIBUTORS Original Filed Oct. 15, 1948 4 Sheets-Sheet 3 CORRECTOR CIRCUIT CRYSTAL OSCILLA'I'OR I'IPULSE FREOUENCV DIVIDER SOUMER AND MPLIFIER INVENTOR REGINALD G. SCHULER ATTORNEY 1954 R. G. SCHULER 2677,725

TELEGRAPH RECEIVER UTILIZING ELECTRONIC DISTRIBUTORS Original Filed 001:. 15, 1948 4 Sheets-Sheet 4 IOB H2 H3 CIIANNEL PHASE SOURER FREQUNCY SHIFTING AND DIVIDER NETWORK AMPLIFIER INVENTOR REGINALD G. SCHULER ATTORNEY Patented May 4, 1954 UN [TED STTES TELEGRPH'RECEIVERUIILIZING EIJECTRONIC DISTRIBUTORS Reginald G. Schuler, Barring-ton;lll., assignor to Teletype Corporation, Chicago, Ill. aeorporationof Delaware 6 Claims. 1

The present invention relates to telegraph apparatus anti systems and more particularly to multiplex telegraph-apparatus ancl systems of the electronictype.

This applicationis a division of copenciing application SerialNo.5476S- fileci October 15, 1948, now Patent No. 2622153 December 16, 1952.

The normal practice in multiplex telegraphy is to transmit from aplurality of channels of intelligence by means of a single mechanical distributor which is-connected to the plurality of sources of intelligence and which during each cycle of operation transmits the correct impulses for theparticular signal of each channel. The scheme of transmission may be of two types; one,

transmitting all of theimpulsesof the signalfor one; channel anclthereafter successively transrnitting. ali of the =impulses;fon theremaining channels separately or; two, by transmitting the first impulse for the first channel anti-theraafter the first impulse for theremaining channels and then repeatingby transmitting the seconci impulse, etc., similarly. It isusual practice to transmit from not morethan-four sources or channels of information.

The above systems which are known and now in use operate satisfactorily with the exception that because of the use of a mechanical distributor and its Component elements, it requires a considerableamount of adjustment and=maintenance because of normal =wear of parts.

Further, when sucha systemis op erated at a high speed. there is a tendency for the brush of the distributor which is traversing the individual segments, or the sequentially closing contacts, to

bounce resulting in, poor signal transmission.

parts.

A second object of thepresentinventionis to provide multiplex telegraph apparatuswhich is almost entirely electronic.

A urther object of the present inver1tion is to provide multiplex telegraph apparatus u.tilizing electrom'c distributors.

Still another object of the present inverltion is to provide multiplex telegraph apparatus utilizing an 1BC7I'OIIC distributor operating at impulse frequency and azi electronic. distributor ope1ating at channel requency in orderto. prvide fo'r the proper transmissionof signals.

A still further object of the present nvention is to provide multiplex telegraph apparatus utilizing two electronicdistribtors which are controlled bythe same frequency source at different speeds of operation.

Yet anotherobjectof the present invention is to provide controlfor a signal initiating device 01' recording device.bymeans of the operation of an electronic channel distributor..

. Further features and advantages of the apparatus embodied in the present invention will become apparent from the following detaileddescription thereof whenread in conjunction with the accompanying drawings, in which:

Figs. 1 and 2illustrate schematically the transmitting apparatusfor use in a multiplex system, when assembled with Fig. 1 to the left of Fig. 2, and,

Figs. 3 and 4illustrate schematically the recei-ving apparatus for use in a multipleXsystem, when assembledwithig; 3 to the left of Fig. 4.

The transmitting apparatus provides generally a plurality of sourcesof signals for transmission, suchfor instance, as from four tape sensing devices, which are well known in the art. A source of oscillations isprovided which operate two fre quency dividers to provide potentials for operating anelectronieimpulse distributor and an electronic ehanneldistributor atthe proper frequency bfoperation in order to provide proper signal transmission. Both of the electronic distributors are of the ring type which after they have completed a cycle of operation willinitiate a followingsimilar cycle ofoperation. A plurality of secondary or matrix tubes areprovided for each channel of transmission, the1e being a number of tubes in each group equal tothe unit code of transmission. The matrix.tubes areuntier the conjoint control of the signal initiating devices, the impulse distributor output, and the "tem has transmitted aparticular signal.

The receiving apparatus comprises generally a pluarlity of matrix tubes which are under the controlof a line relay connectedto the signaling ;channel. Thematrix tubesare controlled simi- -larly: to those at thetransmitting station by means of an impulse distributor ancl achannel distributor which are both electronic and are both controlled astospeed of operation byfrequency dividers perting under the cont1ol of a common crystal oscillator. A corrector circuit is provided to insure that the receiving apparatus Wi1l operate at a speed commensurate With that of the received signa1s. Means are also provided under the control of the channel distributor to cause the operation of the recording device in accordance With the received signal.

Referring now to Figs. 1 and 2, it may be seen that a crysta1 controlled oscillator indicated generaily by the numeral l i has been provided. The osciliator M is shown in b1ock diagram only and may be any of the types which are well known in the art, such for instance as the well known electron coupled osciliator.

The output of the crystal oscillator M is fed over obvious circuits to a pair of frequency dividers indcated generally by the numerals E2 and 13. The frequency dividers have been illustrated in block diagram on1y as such are well known in the art, and may be of the type disclosed in Patent No. 2,410,389 issued to E. Norrman on October 29, 1946. The two frequency dividers 12 and i3 are provided to initiate a requency output diferent to each other, which vvi11 become apparent during the foliowing description of the apparatus. However, it is obvious that if the two diierent required frequencies could be derived from a single requency divider by tapping it at diierent stages a single one would suiixce.

The output of the frequency divider i2 is inipressed over an obvious circuit to a squaring and amplifying device indicated generaily by the numerai !4. The device i4 has been illustrated in block diagram on1y, as squaring and amplifying tube circuits are we11 known in the art. The positve puise output of the device 14 is impressed on a conductor 16.

The output of the frequency divider |3 is impressed over obvious circuits and through a phase shifting network indcated generally by the numeral l'l and a squaring and amplifying device indcated generally by the numeral l8 to a conductor i. Both the network 'I and the device IS have been illustrated in block diagrams as tube circuits or accomplishing such unctions are well known to those versed in the art.

'Ihe output of the frequency divider i2 as squared and amplified by the device 14 and impressed on the conductor l6 wi1i be such that positive operatins pulses will be impressed on such conductor at intervals indicative of the impulse speed of transmission of the various signals. '1hat is, a positive pulse on the conductor E6 wi11 occur to initiate a signal impu1se and the succeeding potential pulse on the conductor 6 wi1l define the end of the signal impulse, and likewise the initiation of the succeeding impuise.

The positive pulses on the conductor 55 are impressed over branching conductors such as 2i and through condensers such as 22 to the norma11y negatir ely biased control grids of five gas filied tubes 24 to 23, inclusive, of the Thyratron type. 'Ihe tubes 24 to 223, inclusive, form an electronic distributor of the ring type, each of the tubes being of the variety that once rendered conductilg wi1l continue to conduct irrespective of grd potentiai until the proper alteration occurs in the cathode or anode circuit. With respect to the instant embodiment it should be assumed that one of the tubes such as 24 is conducting at this time. While no start circuit for the tube 24 has been illustrated, nor any of the other tubes 25 to 23, inclusive, it may be readiiy understood that such may be done by providing a manuaily operab1e contact or push button in the grid circuit of any one of the tubes so that upon the closur of the same, battery will be supplied of a sufficient value to offset the normal negative bias on the control grid of that tube and thereby allow it to be rendered conducting. A similar start circuit has been illustrated in copending application Seria1 No. 596,295, filed on May 28, 1945, in the name of T. A. Hansen, now Patent No. 2,609,452.

If it be assumed that the tube 24 is conducting, positive potential will be impressed from its cathode output circuit through suitable resistors and over a conductor 3| to the control grid of the succeeding distributor tube '25. Ihis potentiai in itself will not be sufficient to raise the valueof the grid sufiiciently high to cause the tube 25 to be rendered conducting but instead acts as a conditioning potential. At such time as the next positive impulse is received on the common conductor 16 and impressed over branghing conductors such as 21 and through condensers such as 22 to the control grids of all of the tubes 24 to 28, inclusive, only tube 25 will be rendered conducting, which tube is receiving a conditioning potential over the conductor 3I. It might be noted at this time that the tube 24 wi1l no longer have its starting device closed at this time, such being c1osed momentarily only for a time sufficient to allow the tube 24 to be rendered conducting.

The positively energized anodes of the tubes 24 and 25 are connected together by means of a conductor 32 and a condenser 33. The condenser 33 is of the commutating type and acts when the tube 25 is rendered conducting to extingush the tube 24. The use and action of commutating condensers are well known in the art and are described in detail in the above menticned copending application in the name of T. A. Hansen.

The succeeding tubes 26 to 28, inclusive, are connected in a manner similar to the tubes 24 and 25, so that as any one of the tubes conducts it supplies conditioning potential over a conductor such as 3! to the control g1id of the associated succeeding tube. Likewise, the anodes of succeeding tubes are connected together through comlnutating condensers such as 33 which causes a preceding tube to be extinguished upon the initiation of conduction in a succeeding tube. In view of such interconnections t may be seen that each of the tubes 24 to 21, inclusive, supp1ies conditioning potentiai for a succeeding tube over obvious circuits so that upon the receipt of the next positive impulse on the common conductor I6 a succeeding tube wil be rendered conducting. Also, at such time the preceding tube Will be extinguished through the use of commutating condensers.

In order to complete ring operation of the impu1se distributor tubes the last tube 28 of the series has its cathode output circuit connected through suitable resistors by means of a conductor 34 to the control grid of the first tube 24 in the series. Therefore, at such time as the tube 28 is conducting a conditioning potential will be impressed over the conductor 34 to cause the tube 24 to be rendered conducting upon the receipt of the next ositive pulse on the common conductor I6. A1so, the anode of the last tube 28 in the series is connected over a conductor 36 and through a commutating condenser 31 to the anode of the first tube 24 in the series. Thus, at such time as the tube 24 is rendered conducting, it w1l cause the tube 28 to be extineuished.

similarly as described with respect to the other commutating condensers.

A time delay network is provided in the conditioning outputcircuitof one tube andthe control griol circuit of the succeecling tube, whieh is composed of the resistor-concienser combination, in order that the action between each pair of tubes will be as described above, and no two tubes will be successively rendered conducting by the same c1riving impulse.

The impulse distributor, its components, and its marmer of operation as described above are a1i described and illustrated in detail in the copending previously mentioned application in the name of T. A. I-Iansen.

The positive pulses which are impressecl on the conductor I9 from the channel requency divider I3 and through the phase shifting netwerk I'I and the squaringand amplifyimg device I!3 are impressed through individual condensers to the normally negatively biased control grids of a pluralty of gas filled tubes 4I to44, inclusive, of the Thyratron type. 'I'his potential is not suiicient in itseli to cause any of the tubes 4! to 44, inciusive, to be renderecl conducting but acts as an operating potential under ccnditons about to be described.

In the following descrption it shouid be assumed that the tube 4! is conducting, having been rendered in suchcondition by a start circuit similar to that desribed above, or having been nitiateci by a start circuit associated with one or the other tubes 42 to 44, inclusive, and the distributor having stepped to a position that tube 4! will be conducting. During the interval that the tube 4I conducts, potential will be impresseci from its cathodeoutput circuitthrough suitable resistors and over a conductor 46 to the control grid of the succeecling tube 42. This potential wiil not be sufiicient "to overcome the negative tubes 4! to 44inclusivethe' tube42 will be rendered conducting.

The anodes of the tubes 4! and 42 are connected by means of a, conductor 41 and a commutating condenser 48 in such manner that'upon the tube 42 becoming conducting the tube il will be extinguished.

The ring operation of the tubes 4;I to 44, inclusive, with one tube conditioning the succeeding tube, with the latter becoming conducting .upon

the receipt of the next postive pulse initiatedby the requency divider 13 and the extinguishment of the preceding tube through the use of the commutating condenser in the anode circuits is sirni lar to that described with respectto the impulse distributor and is also similarto that illustrated and described in the copending T. A. Hansen appiicatcn, and thereforeneednot be repeated.

The electronic distributor ormed by the tubes 4! to i4, inclusive, may be considered a channel distrib-utor in that each of the tubesj4i to 44, inclusive, wi1l remain conducting for a period of time suflicient to allow the mpulse distributor to make a complete cycle of operationwthtne tubes 2ii to 28, inciusive, all becomingconducting ancl extinguishecl or their predetermined interval of operation. Such timing of operation between the tubes24 to 28, inclusive, and 4! to -44, in-

clusive, isprovided throughtheuse of the-mpulse frequencydivider 12 and thechannel re- 6 quency divider H5; that is, the impuls frquency divider l2 wi1l supply asufiicient number of positive pulses to the conductor l8 to allow a compiete cycle of operation of the tubes 2 1 to 28, inclusive, during the interval between successive pulses from the channel frequency divider B to the conductor I9. In this marmer the five impulses comprising a signal on one channel will be transmitted through the operation of the tubes 24 to 28, inclusive, during which interval the tube il will be conducting. Thereafter the five impulses for each of the remaining channeis will be transmitteci during the intervals that the tubes 42, 43, and 44 are conducting, in a manner as will appear hereinafter. The phase shifting network l permits exact syn0hronisrn of the -two distributors to be obtained, so that the channel distributor advances at the same instant that the impulse distributor completes its cycle.

Four signal initiating means indicatecigenerally by the numerals 5! to ineiusive, have been provded, one each controliing a channei of transmission. The signal initiating ineens 5i te 54, inciusive, may be tape sensing devices which are weil known in the art, or may be startstop te multiplex extensors such as are discloseci in U. 8. Patent No. 2,382,596 issued to W. J. Zenner on August 14, 1945, er as disclosed in copending application Serial No. 54,775, led on 0e tcber 15, 1948, in the name of D. Slayton, now Patent Io. 2,532,2i8, in the present embodment the ci"vices 5! to inciusive, have been iilus trated as tape sensing devices each having five contaots whieh are set peranutatably in accordancs with the sensing of the signal impulses in a tape. If .a marking condition exists the contacts would. be so positioned as to be in engagement with a sommen bus such as 56 in the device which is connected over a connncn conductor 5! to a suitable source of battery. I a spacing condition exists the contacts are open as ilius trated.

The, contacts of the device 5! are connected individually to the anoc'ies of iive seccndary or matrix dualgrici vacuum tubes 8 to 552, inclusive, which are associated with the first 01 A channei of transmission, and which is eontroiied. by the A channei distributor tube 4.

The ccntacts of the device 52 are iiizewise connected individually to the anodes of ve seccndary or matrix tubes to inciusive, which are associated with the B channel of transmission, and which is controlled by the B channel distributor tube 42. The tubes 34 to 58, inclusive, are dual-grid vacuum tubes.

In a similar manner the contacts of the signai initiating device 53 are connecteci individuaiiy to the anodes of ive seccndary o1 matrix vacuum tubes 'iii to 'i, inclusivc, which are associated with the third 01 C channel of transmission, &I1l which is contrcllecl by the C channei distributortube 43.

Finally, the contacts of the fourth device5 i are connecteci individualiy to the anodes of ive seccnclary or matrix vaeuurn tubes to 38, inciusive, which are associateci with the D chan-- ne1 of transmission, an wioich is controlled the D channel clistributor tube 44.

If it be assumed again that the A channel distributor tube i is conducting positive poten tial will be impressed frozn ts output cathctie circuit nct nly over the conductor to the succeeding tube 432, but aiso over a conductor anti through suitable resistors to the normally hegativeiy biased sereen grids of the matrix tubes 58 to 62, inclusive. The potential impressed on the sereen grids of the tubes from the common conductor 82 is not sufiicient to cause any of these tubes to be rendered conducting, since ther contro1 grids sti1l are negatively biased, but instead acts as a conditioning potential.

Simi1arly, if the tube 42 had been conducting at this time t would impress positive potential from its output cathode circuit over a common conductor 86 to the normally negatively biased sereen grids of the tubes 64 to 68, inciusive. Such potential a1one, however, is not sufficient to cause any of the tubes 64 te 68, inciusive to be rendered conducting but instead acts as a conditioning potential.

Likewise, if the C channel distributor tube 43 had been conducting at this time it would impress positive potential from its output cath- 0de circuit over a common conductor 81 to the normaliy negatively biased sereen grids of the tubes to '55, inciusive. Such potential a1one is to be rendered conducting out instead acts as a conditioning potential.

Finaliy, if the D channei distributor tube 44 had been conducting at this time it would impress positive potentiai from its output cathode circuit over a common conductor 83 and through suitable resistors to the normaiiy negatively biased screen grids of the tubes 16 to 80, inclusive. This potential is not sufiicientiy high, however, to cause any of these tubes to be rendered conducting by itseif but serves as a conditioning potential.

Assuming at the same time that the tube 24 is conducting, positive potential wi1i not only be impressed from its output cathode circuit over the conductor 3! to the control grid of the succeeding tube 25, but a1so will be impressed over a common conductor 89 and through suitabie resistors to the normaily negatively biased control grids of the No. 1 matrix tubes 58, E4, ii and '!'6 of the four channels A to D, inclusive. The potential impressed on the conductor 89 will act as an operating potential to cause one of the tubes 58, 64, 16 01 76 to be rendered conducting, assuming anode potential to be present, in accordance with which one of these tubes receives a conditioning potential on its screen grid from its associated channel distributor tube 41 to 44, inclusive.

As it has been assumed in the description above that the channel distributor tube 4! and the impu1se distributor tube 24 are both conducting at the same time the matrix tube 58 wii1 be the only one which wii1 at this time receive potentia1 on both its screen and control grids to allow it to be rendered conducting, assuming again that anode potential is present.

If it is further assumed that the signai initiating device 5l has sensed a signai with the No. 1 impulse position marking the first contact will be in engagement with the common bus 56. Whi1e the connection between the contacts of the device 51 and the anodes of the tubes 53 to 62, inclusive, has been shovvn as a cabie ii, should be understood that the first impulse position contact will be connected to the anode of the tube 58, the second impulse contact to the anode of the tube 525, etc. Under this condition, with the first impulse contact in a closed or marking position and with conditioning and operating potentials on the sereen and control grids, respectively, of the matrix tube 58 a circuit will be established which may be traced from positive battery, over the common conductor 51 to the bus 56, through the first impulse contact in the device 5I which is assumed closed, over the cable connection to the anode of the tube 58, through the tube 58, which will be rendered conducting, to its cathode and thence over an obvious circuit to ground. 'Ihus, under this condition the tube 58 will be rendered conducting.

If an assumption had been made above that the signal initiating device 51 had sensed a signal with a spacing condition in the No. 1 impulse position the contact assigned thereto would not be closed and in engagement with the common bus 56. Therefore, under this condition even though both conditioning and operating potentials had been applied to the sereen and control grids, respectively, of the matrix tube 58 the tube would not be rendered conducting because no positive potential would be present from the conductor 51 to the anode thereof.

With the tube 58 conducting a potential drop will occur both on the common conductor 51, and. a conductor 9I which are connected through a common resistor to positive battery. A similar potential drop wi1l occur in a D. C. amplifier, or inverter and amplifier, indicated generally by the numeral 92 and connected to the conductor BI. The unit 92 has been indicated in b1ock diagram as amplifiers or inverters, and amplifiers are well known tube circuits to those versed in the art. The output of the unit 92 is connected to a signaling channel for transmission of telegraph signa1s to a remotely iocated receiver. The unit 92 vviil be either an amplifier or an inverter and ampiifier depending on the scheme of transmission, that is, whether a battery condition on the signaling channel wil1 signify a spacing or a marking condition.

If the assumption had been made, as described above, that a spacing condition had been sensed in the No. 1 impulse position with the tube 58 not being rendered conducting during its interval because of lack of battery on its anode no potential drop would exist on the conductor 9! and, therefore, the unit 92 would cause transmission of a signa1 of an opposite condition to that described above.

As it was also described initially that the A channal distributor tube 4| remains conducting for a period of time during which the impulse distributor as exempiified by the tubes 24 to 28, inclusive, makes a cyc1e of operation, the tube 25 will be next rendered conducting and the tube 24 extinguished, all in a manner as described. Under this condition, the only matrix tube which wi11 receive both a conditioning potential from the tube 41 and an operating potential from the tube 25 will be the No. 2 impulse matrix tube 59. Therefore, the tube 5'J wii1 either be rendered conducting or be not rendered conducting in accordance with the setting of the No. 2 impulse contact in the signal initiating device 5l, in a. manner as was described with respect to the No. 1 impulse contact for either a marking or spacing condition.

Similarly, th tubes 26, 27 and 28 will a11 be rendered conducting for their predetermined intervals during which time signa1s will be transmitted in a manner as described for the numbers 3, 4 and 5 impulse positions of the signal. It might be noted at this time that the distributor tubes 24 to 28, inc1usive, wil1 each remain conductng for a period of time to allow a complete signal impulse to be transmitted over the si 7 naling channel whether it be a marking or spacing condition. Further, any of the matrix tubes such as 58 which may be rendered conducting will only remain conducting for the interval of time that their associated distributor tube such as 2& is conducting, for thereafter operating potential will be removed from the conductor such as 89 and as the matrix tubes are all of the vacuum variety they will no ionger remain conducting irrespective of their anode potential.

After the impulse distributor has completed its cyc1e to allow the five signal impulses of the A" channel' to be transmitted over the signaling channel the 3 channel distributor tube d2 will be rendered conducting and the A channel distributor tube 4I extinguished, a11 as described above. Under this condition positive potental wi11 no longer be impressed to the sereen grids of the tubes 58 to t2, inclusive, over the common conductor 82 bui; instead conditioning potential will be impressed over the common conductor 86 to the sereen grids of the B channel matrix tubes 64 to 68, inclusive. Thus, as the impulse distributor now completes a second cycle of operation, signals will be transmitted over the signalng channel in accordance with the setting successively of the B channel matrix tubes 64 to 68,

inclusive, whch in turn are controlled by their respectve contacts in the signal initiating device 52.

After the above cycle is completed similar cycles wiil be likewse completed for the C and "D channels as the. tubes 43 and 44, respectively, are rendered conducting. In the above 1nanner it may be seen that the first signai is transmitted successively for the A" B, C, and D channels and thereafter the above cycle of the channe1 distributor will be repeated to allow the second character on each channel to be transmitted in succession. The above repettion occurs until such time as all rnessage material available has been transmitted or until the apparatus is shut oi.

In the above description the apparatus was shown as consisting of components necessary for the transmission of a fixe unit code and of four channels of transmission. It is obvious, however, that both the unit code and the number of channe1s may be altered by altering the impulse distributor and/or channel distributor, lilrewise the number of matrix tubes and increasing or decreasing the frequency output from the requency divider 2 and/or the frequency divider I3 correspondingly.

In the above description it was mentioned that after a signai. selection was set up in the signal initiating device the impulse distributor and channel distributor operated through conduction of the tubei and the tubes 24 to 28, inclusive, to transmit the signal over the signaling channel indicative of the partcular signal seiection. After the transmission of such signal indicative of the A channel signal the channel distributor wii operate with the tube 42 being rendered conducting and tube 41 extinguished. Under this condition the signal initiated in the device 52 will be transmitted indcatve of the B channel signal selection. It is obvious frozn the above that during the intervals that signais are being transmitted from the signal initiating means 52, 53 and 54, which wil occur after the transmission of the signal in the initiatng means i, it bec cme desirable to cause a new signai selection to be initiated in the device 5i in readiness for the next interval of transmission of an A channel signal.

After the A channel sign al has been transmitted the tube 42 is rendered conducting, as described above, which results in positive potential being impressed on its cathode output circuit and thence to the conductor 36. Potential will also be impressed from the conductor to a branching conductor 93 and. through a condenser 94 to the normally negatively biased controi grid of a gas filled tube 9%. Because of the condenser a positive pulse only will be impressed on the control grid of the tube 96 at the time tube 42 first conducts, but this pulse will be suficient to render tube & conducting, irrespective of the interval of conduction of the tube 42. The anode of the tube 96% is connected over a conductor 97, through the winding of a magnet 98, over a conductor 99 and through the normally unattracted armature Hit of a reiay IJi2 to positive battery. Therefore, with the relay I2 -de-energized and the armature ii unattracted, the tube 96 will be rendered conducting at this time and the magnet energized. The magnet 98, while not shown with the unit M, is assumed to be the 1nagnet utilized fo stepping the tape sensing device, which in ether words, causes the tape sensing probes to be removed therefrom and the tape to be advanced one character length.

The relay ie? is also connected to the source of positive battery by means of the unattracted armature it! and the conductor 99 and thence compietes ts circuit over the conductor ii and through the tube Hovvever, a condenser N13 is paced in shunt relationship with respect to the winding 03? the relay I02 and, therefore, such relay wiil not be energized immediately upon the tube being; rendered conducting. However, a predetermned time interval the charge on the condensor H33 wil] accumulate through series resistor rom conductor 99, allowing a potential drop across the winding 0 the relay ii2 thereby causing it to be energized. As the relay becomes energized it attracts the arma ture iii thereby breaking the circuit which had been established previously to supply positive battery to energize the magnet 93, the relay ld2, and to support conduction in the tube Therefore, at this time the tube will be extinguished and the magnet Q8 and the relay li2 de-energized. The time delay supplied by the condenser !i ailows the magnet 953 to remain energized for a predetermined interval of time before the reiay 592 is energized to break a11 connections to positive battery at its armature Iii2 and is sufiicient to ailow the tape stepping device in the unit 'l to be operated. The action of the condenser i3 also delays the release of the relay i2, thereby insuring complete extinguishment of tube It inight be noted that if the unit 55 is an extensor rather than a tape sensing device that the magnet 93 or the pulse on the conductor 95 may be utilized to cause the next character to be set up in the extensor.

It should be noted that only one of the circuits for causing the next character to be selected in the units i to 56, inclusive, has been illustrated and described, that being the one assocated with the unit 5%. However, it should be understood that it is contemplated that three similar circuits wiii be provided which will be associated with the output of the tube for the unit 52, the output of the tube i for the unit 53, and the output of the tube i for the unit 5@. In this manner sufficient time is allowed to set up characters for an of the channeis after each character has been transmitted and prior to the time that the multiplex transmitter is ready to transmit the subsequent signal for that particular channel.

The electronic receiving apparatus contemplated for use with the above described transmitting apparatus is iliustrated in Figs. 3 and i. Referring now to these figures it may be seen that a crystal oscillator N35 is provided which is illustrated by a b1ocr. diagram and is similar to that describeo'l Witn respect to the transmitting apparatus. The output of the crystal osciilator I is impressed over obvious conductors to an inipuise frequency divider I'l and a channei frequency divider l8, both of which are iilustrated in bleek diagram and are of a type identical with that described for the transmitting apparatus. The output of the impulse frequency divider Ifll is impressed through a squaring and amplifying circuit H9 to a conductor HI. The device !i19 has been shown in b1ock diagram as such circuits are conventional and well known to the art.

The output of the channel frequency divider N18 is impressed through a phase shifting network H2 and a squaring and amplifying device H3 to a conductor i IJi. Both the netwerk H2 and the device !3 are shown in block diagram on1y as they are simiiar to the units contemplated or use at the transmitting station and are both we11 known in the art.

The output from the impu1se requency divider Hit as squared and amplified by the unit H9 and impressed as a series of positive pu1ses to the conductor III are further impressed to the norma1ly negatively biased control grids of a plurality of gas fi11ed tubes H6 to l2ll, inciusive, through appropriate branching conductors and condensers. The tubes [8 to 120, inciusive, form an impulse distributor similar to that disciosed and formed by the tubes 24 to 28, inc1usive, in the transmitting apparatus. Inasmuch as the tubes H6 to 12%, inclusive, are interconnected and operate in a marmer identical with that of the corresponding tubes at the transmitting appara tus to form an e1ectronic distributor of the ring type it is not deemed necessary to repeat the description of the circuits or operation at this time.

The output of the channel frequency divider H38 which is adjusted to proper phase by the net work H2 and squared and amplified by the device i I3 to resu1t in a plurality of positive pulses on the conductor I N are impressed over branching conductors and through appropriate con densers to the normaliy negativeiy biased contro1 grids of a plurality of gas filled tubes G2! 130 124, inclusive. The tubes 12! to [24, inclusive, form a channei distributor of the ring type which is identicai in operation and interconnection as that ormed by the tubes 41 to M, inciusive, in the transmitting apparatus. Thus, as the two channel distributors are identicai in circuit connections and operations it is not deemed necessary to repeat the description of the one ormed by the tubes I2I to I24, inclusive, at this time.

The signais being transmitted from the transmitting apparatus, described previousiy, over the signalng channing will be received in the winding of a 1ine relay 52%, the opposite terminal of which is shown connected to ground. The 1ine re1ay i2 controls its armature i2i' in accordance with the received signals, the relay i26 becoming energized upon a marking condition and causing its attracted armature 12? to be in engagement with a conductor leading to positive battery. Upon a spacing condition being received in the lne re1ay |28 W11 remain deenergized with its armature I2'l unattracted and 12 in engagement with an unconnected conductor. Thus, at this iatter time no battery is supplied to the armature 121.

t may be seen that output from the squaring and ampifying device 199 is also impressed over a conductor I23 to a corrector circuit I 29 i1- lustrated in biock diagram only. The armature 52? of the line relay [26 is connected by means of a conductor l3l to the corrector circuit [29. The output of the corrector circuit I29 is connected over an obvious circuit to the crystal oscillator HBS. It is contemplated that by use of the just described connections to and from the corrector circuit 129 the receiving apparatus may be operated at 2. speed commensurate with that of the received signals. While the corrector circuit 529 is shown in a b1ock diagram on1y t is contemplated that the corrector circuit utilized with the present apparatus will be similar to that disclosed and described in ccpending application Serial No. 54,773, fi1ed on October 15, 1948. in the name of T. A. Hansen, now Patent No. 2,595656. Accordingly, such app1ication is incorporated herein to the extent necessary for the correct and efficient operation of the described telegraph system.

During the interval that the tube 12! is conducting, positive potential will be impressed from its cathode output circuit over a, conductor [32 and through appropriate resistors to the normaliy negativeiy biaseo. screen grids of a plurality of secondary or matrix gas tubes I33 to [31, inciusive. The matrix tubes l33 to 131, inciusive, are similar to the corresponding matrix tubes at the transmitter assgned to the A channel in that the potential applied to the screen grids is not suiicient to cause the tubes to be rendered conducting. The only diierence between the corresponding sets of tubes is that the instant ones are of the gas filled type and, therefore, onze rendered conducting wi11 continue to conduct irrespective of grid potential until the proper change occurs in the anode or cathode circuit.

The output of. the B cham1el distributor tube 222 is connected by means of a conductor l39 and through suitable resistors to the normally negatively biased screen grids of secondary or matrix tubes IJii to H15, inclusive. The tubes I4I to 145, inclusive, are similar to those described as beng the A channel matrix tubes, I33 to I31, inclusive, and operate in a simi1ar manner.

The 0" channel distributor tube I23 and the D channel distributor tube I24 are each a1so connected simiiariy to a plurality of five associated matrix tubes. Inasmuch as the structure and operation of these tubes will be similar to that with respect to the tubes for the above clescribed two channels it is not deemed necessary to go into detail in describing their connections and operations.

The output of the No. 1 impulse distributor tube H6 is impressed over a conductor 14'! and through a condenser to the normally negatively biased control grids of the No. 1 impulse matrix tubes for a11 four channels, such as the tubes |33 and ii for the A and B channels, respective1y. The connection of these tubes is thus dis similar to that describecl at the transmitting apparatus, and the potential applied to the control grids due to the operation of tube H6 consists of a positive impulse at the instant that tube l 18 begins conduction and a negative impulse when it ceases to conduct. The positive potential im pu1se on the controi grid is not sufficient in itse1f to cause the matrix tubes tobe rendei'ed"con-- ducting even though conditioning potential exists 011 the sereen grids from the output of the appropriate channel distributor tube unless a secondary conditioning potential is appliedfrozn a third source, as will be hereinafter described. The negative impulse has no eiect in thecontrol of gas type tubes. tributor and channel distributor will be dissimi- 1ar to that described for the transmitting apparatus with the channel distributor operating between the times that the impulse distributor tubes operate. This is in order that the channel distributor may condition the sereen grids of a par.

ticular channel set of matrix tubesin advance of the time that the impulse distributor begins en ergizing the control grids of the Same. matrix tubes.

The armature |21 of the line relayi26 is een: nected by means of a conductor [48 to circuits to the control grids of all of the matrix tubes f01 a11 four channels. However, even though a marking conditicn exists on the conductor |48 as will be described the potential applied to the control grids of all of the matrix tubes will not in itself be suiicient to allow one or more of the;tubes to be rendered conducting.

If it now be assumed that a marking conditon is being received on the signaling channel for a particular impulse the line relay 126 will be energized and will attract its armature 121 to its ieftward position. Under this condition positive battery will be connected to the armature I2'I and thence over the conductor I48 to the control grids of all of the matrix tubes; FI'OIII adescription of the transmitting apparatus itwi1i be remembered that it was described that only one of the channel distributor tubes wi1l beconducting at any one time and supplying conditioning potential to the sereen grids of its associated matrix tubes. Therefore, let it be assumed that the A channel distributor tube 12! is conducting and supplying potential to the sereen grids of its associated matrix tubes [33 to [31, inclusiva Likewise, under the described condition, the armature E 2! and the conductor 148 wili.be supplying -positive potentiai to the contro1 grids of thesame matrix tubes I33 to [31, inclusive, and to all other;

matrix tubes.

Under the above conditions atsuch time as any one of the impulse distributor tubes H6 to I20,

inclusive, is rendered conducting, potential will" positive potential impulse wii1 be impressed over the conductor IJi'i to all of the No. 1 impulsematrix tubes such as I33 and I4l. With thethree potentials being present on the screen andcontrol grids of the tube I33 at this time, the tube !33 Wi11 be rendered conducting. It should be noted that this wil! be the only tube that will have conditioning potential on its sereen grid from its associated= channel distributor tube I'2I,

conditioning potential on its controi grid from the armature i2'i' of the line relay |26 and con ductor 1438, and operating potential on its control.v

grid from its associated impulse distributorytube H5. As the tube 133 is of the gas filledvariety it wi1i be rendered conducting and remain in that condition irrespective of a change in grid potentia1.

If a spacing condition had existed.on the.sig

Thus, if.it be as- The timing of the impulse disbeen energized and, therefore, the armature l2i' would ;have remained in its illustrated unattracted position. Underthis condition no positive battery wouldhave been supplied through the armature l 21 and over the common conductor I48"toserve as conditioning potentiai on the control grids of all of the matrix tubes. Therefore, even .though conditioning potential were supplied to the sereen grid of the tube 33, at such time as operating potential is appliedto the control grid thereof by the impulse distributor tube H6, the tube 133 will. not be rendered conducting as no conditioning potential exists on its contro1 1grid. from thesource associated with the line re- From the above description, it may be seen thatthe various matrixtubes at their interval for selection wi1l be eitherrendered conducting in accordance with a marking condition or remainznonconducting in accordance with a spacing condition.

During the interval that the A channel distributor tube I2l isconducting the matrix tubes I33 to l3'l, inclusive will be operated in accordance with the five signal impulses being received over the signaling channel by the line relay H26. Thus, the signal conditions will be stored in these tubes because they are the type which once rendered conducting wil1 continue to do so irrespective of grid potential.

It might be noted that the impulse distributor formed ofthe tubes I|6 to 20; inclusive, operates in such a manner that the impuises de- 1ivered over the conductors such as l4l wl1 occur at approximately the midpoint of the received line signal interval. Such timing is provided for theoretically the signa1 impulse should be best at this point, considering line distortion, etc. The timing relation between impulse distributor operation and line signal impulse occurrence is controlled and maintained by the corrector |29.

After a11 of the signa1s have been stored in the A channel matrix tubes [33 to [37, inclusive, the channel distributor wi1l operate to cause the tube I22 to be rendered conducting and the tube l2'l extinguished. Under this condition the receiving apparatus is now ready to receive and store the five impulse selections for the B channe1 in the matrix tubes I4I to [45, inciusive. Likewise, as the apparatus continues to operate a signal will be stored for each of the channels C and D and thereafter the cycle W11 be repeated forthe A channel, as described.

It should be noted that the anodes of the A channel matrix tubes I33 to l3'l, inclusive, are connected over individual conductors, illustrated in cable form to a receiving unitindcated gen era1ly in biockdiagram form by the numeral 149. The unit I49.is illustrated as having the con ductors being connected individually to five magnetwindings |5| on1y two of which are shown. Thecircuitmay be further completed over a conductor 152 and through the unattracted armature 153 of a relay |54 to positive battery. Therefore, under the above described conditions, at such time as any of the tubes !33 to I3'I, inclusive receive suflcient conditioning andoperating potential the tube will be allowed to conduct with the anode battery being suppiied through the associatecl winding l5l and unat tracted:armature I53. The windings |5l may be the individual windings of a five magnet printer wbich is well known in the art. However, the windings couidbe replaced by the appropriate elements in a multiplex to start-stop extensor or converter such as the type disclosed in the above mentioned Zenner patent or in copending ap plication Serial No. 54,776, filed in the name of R. D. Slayton on October 15, 1948, now Patent No. 2536578. Thus, the five impulse selections as stored in the tubes 133 to 131, inclusive, will likewise be stored in the unit 149.

After the complete signal has been received in the matrix tubes 133 to 131, inclusive, and likewise in unit 149, which indicates that the entire signal for the A channel has been received, the channel distributor tube 122 will be rendered conducting with the tube 121 being extinguished, all as described previously. At the instant the tube 122 becomes conducting, the positive potential impressed from its output cathode circuit to the conductor 139 will also be impressed over a branching conductor 156 and through a condenser 151 to the control grid of a gas filled tube 158. The anode of the gas filled tube 158 is connected by means of a conductor 159 through the winding of a magnet 161 to the conductor 152, which extends to the positive battery through the unattracted armature 153. Thus, because of the single positive impulse through the condenser 151 the tube 158 will be rendered conducting and remain in that condition because it is of the gas filled variety.

Upon the tube 158 becoming oonducting the magnet 161 will be energized. It is contemplated that the magnet 161 will be, if the device is a five magnet printer, the magnet which releases such printer to cause the actual printing of the character which is stored in the individual windings 151. However, if the unit 149 is an extersor or convertor the magnet 161 will be replaced by suitable components or the positive impulse on the conductor 1515 and through the condenser 151 will be utilizeol to initiate retransmission of the start-stop signal.

The relay 154 also receives positive battery through the unattraoted armature 153 and over the conductor 152, which circuit is completed at such time as the tube 158 is conducting over the conductor 159 and through the tube. However, a condenser 162 is placed in shunt relationship with respect to the winding of the relay 154 and therefore, at such time as the tube 158 is renclered conducting a predetermined interval will exist during which the condenser 162 is being charged through the series resistor until the potential across the relay 154 is sufficent to allow the relay to be energized. The above-mentioned predetermined interval will be sufficient in dure.- tion to allow the magnet 1151 to be energized to serve its purpose in the apparatus.

Upon the relay 154 becoming energized it will attract its armature 153 thereto resulting in positive battery no longer being supplied through the armature 153 to the conductor 152. As it was described previously that the anode potential for the matrix tubes 133 to 131, inclusive, for the tube 158 and the energizing potential for the windings of the magnet 1131 and the relay 154 all were provided from the positive battery through the unattracted armature 153 it may be seen that Upon the relay 154 becoming energized all of the above circuits will be broken. Therefore, any of the matrix tubes 133 to 131, inclusive, which may have been rendered conducting to store a, markng impulse will be extinguished at this time, in readiness for the storage of the next received signal on the A channel. Likewise, the tube 158 will be extinguished with the magnet 161 and the relay 154 de-energized. Under this condition the apparatus will all be in readiness for the receipt of the next A channel signal, the utilization thereof and the resetting of the apparatus to its normal unoperatecl condition. The condenser 162 across the coil of relay 154 sustains the operating current in said relay long enough to insure complete extinguishment of tube 158.

While a detaled descrption has been given with respect to the control circuit for the A channel similar control circuits have been illustrated or the B, 0, and D channels. However, as these operate similarly to that described above it does not appear necessary to describe in detail their interconnections and operations.

From the above description it has been seen that a receiver has been disclosed which operates to receive a five unit code on four channels of transmission. However, it is obvious that either the unit code or channels may be increased or decreased by suitable additions or subtractions in the impulse distributor, channel distributor, matrix tubes, and alteration of frequency output from the impulse frequency divider 18'1' and/or the channel frequency divider 1118, with similar changes being made in the cooperating multip1ex transmitter, as described previously.

While a specific embodiment of the invention has been illustrated and described it is obvious that the invention is not limited to such disclosure but that additions and modifications may be made thereto within the scope and spirit of the invention.

What is claimed is:

1. In a telegraph receiver, signal receiving means for receiving signals from a sgnaling channel, a plurality of groups of matrix tubes conditioned by said signal receiving means, a distributor for conditioning each of said roups of matrix tubes successively, a distributor for operating conditioned ones of said matrix tubes successively in each group, means for driving said distributors at their proper relative speeds, whereby said one distributor conditions each of said groups of matrix tubes and said other distributor operates conditioned ones of said matrix tubes in each group, and separate means for uti- 1izing the received signals under the control of each of said groups of matrix tubes.

2. In a telegraph receiver for separating received signals into impulse positiong and channel positions, signal receiving means for receiving signals from a signaling channel, a, plurality of matrix tubes conditioned by said signal receiving means, an electronic distributor of the ring type for conditioning said matrix tubes in channel po sitions, an electronic distributor of the ring type for causing operation of said matrix tubes conditioned simultaneously by both said signal re- .ceiving means and said channe1 distributor in impulse positions, means for driving said distributors at their proper relative speeds, whereby said one distributor conditions said matrix tubes in channel postions and said othey distributor operates conditioned. ones of said matrix tubes in impulse positions, and separate signal utilization means controlled by said matrix tubes in each channel postion in accordance with the impulse positions.

3. In a telegraph receiving terminal, means for receiving incoming signals from a signaling medium, each of said signals comprising a group of impulses, each succeeding signal group of Ii'lpulses being indicative of one channel of a predetermined number of difierent channels, a distrbutor operating at impulse speed, a distributer operatng at channel speed, separate sgnal uti11- zation means, and means to distrbute the incomng signals rern sad receiving means to said separate sgnal utiiization means under the joint eontro1 of said mpuse dstrbutor and said channe1 distributor.

4. In telegraph reeeving apparatus, a plura1ity of recorders, an eectronic ring channel distrb-utor formed of a plurality of tubes, each of said tubes controliin reeepton in one of said recrders, means to cause the operation of said channel dstrbutor by causng said tubes to be rendered cenductng successively, and means controilee by the rendering conduetng of each of said tubes to cause a received signal to be recorded in the one of said recorders c0ntrolled by the precedng one of said tubes.

5. In a telegraph receving terminal, separate signa] utilization means, an electronic ring channel distrbutor formeel of a plurality of tubes, each of said tubes controlling a separate one of said signal utilizaten means, means to cause the operation of sai channel distrbutor by causing sad tubes te be rendered conductng successively, and means controlled by the renderng conductng of each of said tubes to perform a contro1 function in the one of said signal utilization 18 means controlled by the preceding one of sad tubes.

6. In a telegraph receiver, sgnal receiving means for recevng sgnals from a sgnalng channel, a plurality of groups of matrix tubes conditioned by said sgnal recevng means, a distrbutor or conditioning each of said groups of matrix tubes successvely, a dstrbutor or operatng condtoned ones of said matrix tubes successively in each group, an oscllator, a frequency dvider controled by sad oscillator for operating said distributor for conditioning each of sad groups of matrix tubes, a frequency dvider contro11ed by said oscilla-tor f01 operatng said distributor for operatin conditioned. ones of sad matrix tubes, and separate means f0r utlizng the received signals under the control of said groups of matrix tubes.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1864,074 Krum June 21, 1932 2,345,628 Person Apr. 4, 1944 2,365,450 Blss Des. 19, 1944 2412642 W1kerson Dec. 17, 1946 2,465,355 Cook Mar. 29, 1949 

